MEXICO CITY -- In the labyrinth of this city's historic center, there is almost nowhere left to build. Existing buildings date to the Spanish conquest and are protected from demolition. Where empty lots exist, new structures are height-limited to meet codes regulating the skyline.

There is the Zocalo, of course, the world’s second-largest public plaza after Moscow’s Red Square and the place where Mexicans gather en masse to celebrate, protest or visit the spot where the Aztecs founded their ancient city of Tenochtitlan. But that esplanade is considered inviolable.

So where does a Mexico City architecture firm propose to raise its 70 stories of retail, office, housing and cultural space?

Right there, in the Zocalo. But “raise” is the wrong term. Searching for a solution to sprawl and homing in on how to create new space in the restricted historic center, BNKR Arquitectura has inverted the whole concept of a skyscraper with its plan for an “Earthscraper.”

Shaped like an inverted pyramid, BNKR proposes to build its “tower” 300 meters into the earth beneath the Zocalo. The plaza’s stone would be replaced with glass to let light filter into the plunging building below. The architects say the deepest stories could be lit “naturally” using a new fiber optic technology, still under development in the U.S., that captures sunlight and carries it underground.

The futuristic design respects Mexico City’s “layer cake” of history, says BNKR architect Esteban Suarez. The first 10 stories closest to ground level would serve as a permanent exhibit of all the ruins and artifacts unearthed during construction.

Additionally, the Earthscraper design features 10 stories each of housing and retail space and 35 stories of office space.

The design has garnered international attention—and criticism. After all, Mexico City sits on highly seismic ground. A “tower” digging this deep has never been tried before.

Suarez counters that underground metro stations have gone unharmed in recent earthquakes and, in answering other engineering questions, he points out that the Earthscraper is shaped like a pyramid precisely to relieve the pressure of the earth on the structure.

Suarez notes, however, the difficulty of promulgating such a radical plan in Mexico. He says firm has been waiting months for an audience with Mayor Marcelo Ebrard, so far in vain, and it has even received “hate mail” from locals who view with suspicion any plans to touch the Zocalo.

But that’s not discouraging BNKR.

The project is one meant to “generate dialogue and reflection,” says Suarez. “It’s about finding new solutions to resolve ancient problems.”

Lauren Villagran has written for the Associated Press, Dallas Morning News and Christian Science Monitor. She holds a degree from the Medill School of Journalism at Northwestern University.
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